Blower



0a. 20, 1936. a w. BALLENTINE 2,058,123

BLOWER Filed Dec.. 26, 1935 2 Sheets-Sheet l jade (Saw-2e 145mm. @x ,4; z

1936. E. w. BALLENTINE 1 2,053,123

BLOWER Filed Dec.- 26 1935 2 Sheets-Sheet 2 blower must operate.

Patented Oct. 20, 1936 BLOWER Earle W. Ballentine, Chicago, llll., assignor to Solar Industries, Inc., Chicago, lill., a corporation of Illinois Application December 26, 1935, Serial No. 56,293

/ Claims. (Cl. 230-120) This invention relates to improvements in fanblowers, and more particularly to blowers adapted to work against pressure.

One feature of this invention is the provision of a blower which can be manufactured and operated at relatively low cost; another feature of this invention is that the blower moves air against pressure without objectionable noise; still another feature of this invention is that when operated vertically, the air-thrust substantially counterbalances the weight of the fan and shaft, with the minimum friction of rotation; another feature of this invention is that a minimum resistance to free gravity circulation of air is offered when the fan is not operating, as when the blower is used in a furnace application or hot-air duct; other features and advantages of this invention will appear from the following specification and the drawings, in which Fig. 1 is a vertical sectional view of a blower embodying this invention; Fig. 2 is a horizontal view along the line 2-2 of Fig. 1; and Fig. 3 is a.

fragmentary view, similar to Fig. 1, of a modified construction. Where blowers are used in connection with hot-air heating systems, for example, the friction of the ducts and elbows, and other factors, imparts a resistance against which the An efficient blower must therefore deliver air in considerable quantities at a pressure higher than that of the air-source from which it is drawing its supply. The movement of the blades of the fan in the blower, especially where the blower is operating against a certain amount of pressure, tends to set up airbeats which are transmitted upwards through the ducts to the rooms, and are undesirable.

The present invention, through the combination-of a fan and a casing having a partition therethrough, and proper proportioning of the various elements of the combination, results in a blower which will deliver large volumes of air against reasonable pressure differentials without substantially any audible sound waves being set up therein, and do this economically. The invention comprises placing a fan in an opening in an orifice-plate or partition located in a casing, and making the opening only slightly larger than the diameter of the fan and the casing at least 20% larger than the diameter of the fan. I

In the particular embodiment of the invention illustrated herein, a casing I0 is here shown as of rectangular shape. The casing has a partition or orifice-plate ll located therein, which plate has an opening I! therethrough. Mounted in the opening I2 is a fan here shown comprising a hub l3 and two blades It and IS. The hub I3 is supported by the rotating means or electric motor N which motor is in turn mounted on a spider support ll which maintains it in a desired position within the casing l0.

Air is admitted to the blower through the boot or inlet [8 leading to a source of cold air, for example. Above the casing in of the blower is a filter casing IS in which are mounted suitable filters 20 through which the air is forced. It is readily apparent that the frictional resistance of the walls of the casings, the inlet ducts and the delivery ducts leading from the blower, and the resistance of the filters to the passage of air therethrough, all require the development of pressure by the blower in order to deliver the desired volume of air to the rooms, for example.

In the blower disclosed herein the pressure differential is developed across the orifice plate or partition l2, the inlet side being the low pressure side and the delivery side being the high pressure side of the plate. The opening l2 in the plate I I is slightly larger than the diameter of the fan taken perpendicular to the axis or hub at the widest point. In the particular embodiment of this invention illustrated in Figs. 1 and 2, the diameter of the fan is 30" and the diameter of the opening l2 in the orifice-plate II is 32". The

dimensions of the casing H] are 36" by 36", or in other words the diameter of the casing Ill (36") is 20 larger than the diameter of the fan (30").

Th fan disclosed herein and forming a part of the vention in this blower has considerable axial. epth with respect to its diameter, in this case 3 thereof. That is, the distance between the most widely separated points of the two blades, in a direction parallel to the axis, is about 36% of the diameter of the fan. It has been found that the placing of the fan within the opening l2, and its consequent relation to the orificeplate H, is of considerable importance. This placement, the orifice or opening l2 retaining the same relation to the diameter of the fan, depends upon the ratio of the diameter of the casing to the of the fan. When the diameter of the casiri is substantially 20% greater than that of the fan, the fan must be centrally located in the opening H in order to deliver the largest volume of air against the pressure drop found in the system.

As the diameter of the casing Ill is enlarged, the fan must be moved more and more to the low pressure side of the orifice-plate in order to maintain a desired pressure differential between the opposite sides of the plate ll. As illustrated substantially one-third larger than the diameter of the fan, the opening in the orifice-plate remaining unchanged, the fan must be located so that substantially 75% thereof lies on the low pressure side of the plate. As the diameter of the casing is increased still further, the fan must be moved more and more toward the low ,pressure side, until the forward or upward portion thereof is substantially in a plane with the orificeplate and the fan lies substantially on the low pressure side of the blower.

The particular shape and size of the blades of the fan disclosed herein were more particularly described in my Patent No. 1,998,184. It will be noted that the blade, in its greatest dimension, is substantially 75% of the diameter of the fan,

and that it is a fiat plate, substantially rectangular except for the fact that one side is curved in what is substantially the radius of curvature of the fan.

The blades are set at an angle of substantially 30 to the horizontal, or with respect to each other, so that their projection on a surface through the hub at the point of their connection thereto and perpendicular to the hub forms the diameter of the fan in one direction and is only about of the fan diameter in a direction at right angles thereto.

In other words, it has been found that with less inclination of the blades to the horizontal their dimensions should be changed in order to keep the projection between 40 and 80% of the I fan diameter.

While I have shown and described certain embodiments of my invention,'it is to be understood that it is capable of many modifications. Changes, therefore, in the construction and arrangement may be made without departing from the spirit and scope of the invention as disclosed in the appended claims, in which it is my' intention to claim all novelty inherent in the invention as broadly as permissible, in view of the prior art.

What I claim as new and desire to secure by Letters Patentis:

1. A blower adapted to move air against pressure, including: a fan having an axial depth at least 25% of its diameter; a casing having an internal diameter from 2033 larger than that of the fan; an orifice-plate in said casing having an opening therethrough slightly larger than the diameter of said fan, said fan being mounted in the plane of said opening and having from 50% to thereof located on the low pressure side of said orifice-plate; and means for revolving said fan.

2. A blower of the character described adapted to move air against pressure without objectionable noise, including: a two-bladed fan having an axial depth at least 25% of its diameter; a casing having an internal diameter from 20-33%;% larger than that of the fan; an orifice-plate in said casing having an opening therethrough slightly larger than the diameter of said fan, said fan being mounted in the plane of said opening and having from 50-75% thereof located on the low-pressure side of said orifice-plate; and means for revolving said fan.

3. A blower of the character described adapted to move air against pressure without objectionable noise, including: a fan having a hub and two similar blades, said blades being oppositely arranged and inclined with respect to said hub v and attached thereto, each blade having one dimension substantially equal to half the diameter and another dimension substantially 75% of the diameter of the fan; a casing having an internal diameter from 20-33 larger than that of said fan; an orifice-plate in said casing having an opening therethrough slightly larger than the diameter of said fan, said fan being mounted in the plane of said opening and having from 5075% thereof located on the low pressure side of said orifice-plate; and means for revolving said hub.

4. Apparatus of the character claimed in claim 3, wherein said fan has an axial depth of substantially 35% of its diameter.

5. A blower of the character described adapted to move air against pressure without objectionable noise, including: a two-bladed fan having an axial depth substantially 35% of the diameter, the longer dimension of each blade being substantially 75% of said diameter; a casing having an internal diameter 20% larger than the diameter of said fan; an orifice-plate in said casing having an opening therethrough from 5-10% larger than the diameter of said fan, said fan being centrally mounted in said opening and in the plane thereof; and means 'for revolving said fan.

EARLE W. BALLEN'I'INE. 

